ASTM A542/A542M Alloy Steel Sheet,Plate, Chromium Molybdenum

ASTM A542/A542M Alloy Steel Sheet/Plate, Chromium Molybdenum Product Information -:- For detailed product information, please contact sales. -: ASTM A542/A542M Alloy Steel Sheet/Plate, Chromium Molybdenum Synonyms -:- For detailed product information, please contact sales. -:

ASTM A542/A542M Alloy Steel, Chromium Molybdenum Product Information -:- For detailed product information, please contact sales. -: ## **Product Datasheet: ASTM A542 / A542M Alloy Steel Plate (Chromium-Molybdenum)** **Product Overview** ASTM A542 is a **quenched and tempered (Q&T) chromium-molybdenum low-alloy steel plate** specifically designed for **heavy-walled, welded pressure vessels** operating at **elevated temperatures** in corrosive environments, particularly those involving hydrogen service. Unlike the normalized and tempered ASTM A387 series, A542 steel undergoes a rigorous water quenching process, resulting in a fine-grained tempered martensitic microstructure. This provides superior **through-thickness properties, higher yield strength, and enhanced toughness**, especially in thick sections required for large-diameter hydroprocessing reactors and similar critical equipment. It is engineered to meet the most demanding requirements for high-temperature hydrogen attack (HTHA) resistance and creep strength. **Key International Standards** * **Primary Standard:** **ASTM A542 / A542M** - Standard Specification for Pressure Vessel Plates, Alloy Steel, Quenched-and-Tempered, Chromium-Molybdenum. * **Governing Specification:** This product conforms to the specified grade within ASTM A542, which is classified by type based on chromium content and class based on tensile strength. * **ASME Designation:** **SA-542** - The ASME Boiler and Pressure Vessel Code (BPVC) designation. * **Classification System:** * **Type A:** 2.25% Chromium - 1% Molybdenum (similar to A387 Gr.22) * **Type B:** 3.00% Chromium - 1% Molybdenum * **Type C:** 2.25% Chromium - 1% Molybdenum with Vanadium * **Type D:** 3.00% Chromium - 1% Molybdenum with Vanadium * **Classes:** Defines minimum tensile strength (e.g., Class 1: 85 ksi min, Class 2: 105 ksi min). * **Mandatory Heat Treatment:** Supplied in the **quenched and tempered (Q&T) condition**. * **Complementary Product:** Often considered alongside **ASTM A832** for normalized and tempered vanadium-modified Cr-Mo steels. **Chemical Composition (Weight % - Representative: ASTM A542 Type A, Class 2)** *Note: Composition varies significantly by Type. Type A is shown as the most common.* | Element | Typical Requirement (Type A) | Key Purpose | | :--- | :--- | :--- | | **Carbon (C)** | 0.15% max | Controlled for weldability and toughness. | | **Manganese (Mn)** | 0.30 - 0.60% | Hardening agent. | | **Phosphorus (P)** | 0.020% max | Very low for purity and toughness. | | **Sulfur (S)** | 0.015% max | Very low for improved Z-direction properties. | | **Silicon (Si)** | 0.15 - 0.40% | Deoxidizer. | | **Chromium (Cr)** | **2.00 - 2.50%** | Oxidation & HTHA resistance. | | **Molybdenum (Mo)** | **0.90 - 1.10%** | Creep strength and carbide stabilization. | | **Vanadium (V)** | (Only in Types C & D) | Precipitation strengthening (enhances creep). | | **Carbon Equivalent (C.E. IIW)** | Typically 0.45 - 0.55 | Managed for weldability despite high strength. | **Physical & Mechanical Properties** *Properties are exceptional due to the Q&T process. Class 2 (105 ksi min TS) is common for heavy reactors.* | Property | Typical Requirement (Type A, Class 2) | Advantage of Q&T Process | | :--- | :--- | :--- | | **Tensile Strength** | 105 - 135 ksi (725 - 930 MPa) | **High Strength:** Allows for thinner walls or higher design pressures. | | **Yield Strength (0.2% Offset)** | 85 ksi (585 MPa) min | **High YS/TS Ratio:** Often 0.85+, providing high design stress. | | **Elongation in 2" (Min)** | 16% | Maintains good ductility. | | **Reduction of Area (Min)** | 45% | Excellent, indicating high toughness. | | **Charpy V-Notch Toughness** | Strictly specified (e.g., 40 ft-lb @ 40°F / 4°C min). | **Superior Fracture Toughness:** The Q&T microstructure provides excellent resistance to crack initiation and propagation, critical for thick-walled vessels. | | **Maximum Service Temperature** | Up to **~1150°F (621°C)** for Type A. | Excellent creep strength due to fine martensitic structure. | | **Key Feature** | **High-Strength, High-Toughness Q&T Cr-Mo Plate:** Uniquely combines the hydrogen and temperature resistance of 2.25Cr-1Mo chemistry with the superior mechanical properties and through-thickness uniformity of a quenched and tempered plate, enabling the manufacture of safer, more efficient ultra-heavy wall pressure vessels. | **Product Applications** ASTM A542 is specified for the most critical, thick-walled pressure vessels in severe service. * **Heavy-Wall Hydroprocessing Reactors:** **Primary material for modern hydrocracker and hydrotreater reactors**, where maximum resistance to HTHA, high design pressure, and guaranteed through-thickness toughness are mandatory. * **High-Pressure Synthesis Reactors** (e.g., methanol, ammonia). * **High-Temperature / High-Pressure Separators and Flash Drums** in refinery and petrochemical service. * **Power Generation Components** for advanced ultra-supercritical (USC) boilers. * **Thick-Walled Heat Exchanger Shells.** **Advantages & Fabrication Notes** * **Extremely Demanding Welding & Fabrication:** Fabrication is at the pinnacle of pressure vessel technology. * **Preheat/Interpass Control:** Critical, typically **400-600°F (204-316°C)**. * **Low-Hydrogen Practice:** Mandatory, with specialized filler metals (e.g., high-nickel content for toughness). * **Post-Weld Heat Treatment (PWHT):** **Always required.** Temperatures must be **below the original tempering temperature** to avoid softening (typically 1100-1250°F / 593-677°C). Cooling rates are critically controlled. * **Risk of Reheat & Underclad Cracking:** High susceptibility requires meticulous procedure qualification, including use of **buttering layers** (often with stainless steel) on internal surfaces before cladding. * **Superior Through-Thickness Properties:** The Q&T process minimizes the strength drop-off from surface to center, providing more uniform and predictable performance in thick plates (often > 6 inches). * **Enhanced HTHA Resistance:** The fine, tempered martensitic structure can offer improved resistance to hydrogen attack compared to normalized microstructures at equivalent strength levels. * **High Cost & Lead Time:** Requires specialized steelmaking, massive heat-treating facilities, and highly skilled fabrication, resulting in a premium product. **Disclaimer:** This datasheet provides an overview of the advanced **ASTM A542 / SA-542** alloy steel plate series. This material is for **specialized, code-regulated applications only**. Procurement requires detailed specifications defining **Type, Class, heat treatment, and stringent mechanical/toughness properties**. **Design must follow ASME BPVC, Section VIII, Division 2 or 3 rules for high-pressure vessels.** Welding and PWHT procedures require extensive qualification (PQR/WPS per ASME Section IX), often involving full-thickness mock-ups. Fabrication must be performed by **ASME U2 or U3 certified shops** with proven expertise in Q&T Cr-Mo steels. Engineering oversight by specialists in high-pressure/high-temperature hydrogen service is non-negotiable. Improper handling can lead to catastrophic failure. -:- For detailed product information, please contact sales. -: ASTM A542/A542M Alloy Steel, Chromium Molybdenum Specification Dimensions Size： Diameter 20-1000 mm Length <4706 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A542/A542M Alloy Steel, Chromium Molybdenum Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A542/A542M Alloy Steel Sheet,Plate, Chromium Molybdenum -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A542/A542M Alloy Steel Sheet,Plate, Chromium Molybdenum -:- For detailed product information, please contact sales. -:

Packing of ASTM A542/A542M Alloy Steel Sheet/Plate, Chromium Molybdenum -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Sheet/Plate drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1177 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition